Process and composition for making roadways



Patented Feb. 13, 1923.

Mirna. srras JACOB SHOTWELL ROBESON, OF PENNINGTON, NEW JERSEY.

PROCESS AND COMPOSITION FOR MAKING ROADWAYS.

No Drawing.

To all whom it may concern:

Be it known that I, JACOB SHOTWELL Ronnsoma citizen of the United States, and resident of Pennington, in the county of Mercer and State of New Jersey, have invented certain new and useful Improvements in Processes and Compositions for Making Roadways, of Which the following is a specification.

This invention is an improvement in the binding or bonding of mineral aggregates and although it may be used in the making of briquets, building blocks, etc., it is particularly adapted for use in the construction of road Ways, to give a hard. durable. Water resistant surface, resisting or preventing the formation of dust.

My improved binder is preferably prepared in dry finely subdivided or powdered form so that it can be thoroughly mixed with the mineral aggregate in forming the roadway and serve to fill the voids in the aggregate. When mixed and in place it may be sprinkled or moistened and thereby caused to chemically react or unite to form a solid mass or monolithic structure. The binder material when properly mixed, moistened,'pressed and permitted to set is hard, impervious to moisture. and will stand heavy traflic Without breaking up or the production of any appreciable amountof dust. As the main or bulk ingredient of my improved'binder powder. I employ some form of finely ground silicate belonging to that general class of silicates which are attacked by hydrochloric acid (HCl), as an inexpensive, easily obtained, very satisfactory form of silicate mixture. I preferably employ blast furnace slag. Comminuted solids obtained from sulfite cellulose liquor contain ingredients of such nature that in the presence of moisture they react in some way With silicates of the class above referred to and to eventually produce hard solid and durable masses. I have found that the use of magnesium sulfate (MgSO with the other two ingredients gives improved results but I am not prepared to state how it enters into chemical combination if at all but apparently it acts in such a way as to greatly increase the Water resisting properties of the binder.

Merely as an example of a powder which experiencei'shows operates to produce highly satisfactory results; the following ingre Application filed August 3, 1921. Serial No. 489,622.

dients may be mixed in the following proportions.

Blast furnace slag, 82%.

Sulfite cellulose liquor solids 11%.

Magnesium sulfate 7%. I

These ingredients are ground separately or together-and thoroughly mixed so as to form a powder. Although the fineness may be varied, better reaction results when the mixture is finely ground, as for instance, so that the major portion will pass through a 100 mesh screen.

The powder may be mixed in various proportions with the mineral aggregate, depending upon the size and character of the parts of the latter and the purpose for which the monolithic product is to be used. In the construction of a road Way, for which my binder is primarily intended, the following is an example: The road way may be made of inch stone with enough inch stone to fill of the voids and the balance filled by a mixture of two vparts screenings to one part of the binder powder. The manner or order of applying and spreading may follow the usual practice in making macadam roads. After the stone, screening, and powder are in place, the road is sprinkled or wet down with water and preferably thoroughly rolled. The action of the water on the binder powder causes certain reactions to take place which are facilitated by the fine state of subdivision of the ingredients of the powder and the abrasion due to the slight shifting of position of the particles and the presenting of fresh surfaces for chemical attack. Neither sprinkling nor rolling are essential although desirable. The necessary water to bring about the chemical action may come from rains and the rolling or pressing action may be that resultingjfrom the traific on the road-in normal use. The reaction takes considerable time and even if thoroughly rolled the use of the road for ordinary trafiic' tends to further compress and pack down the aggregate and; binder as well as promote the chemical reaction. In course of time the road way becomes a very hard, solid and compact monolith, firmly bound together which will resist Wear and be impervlous to moisture.

The sulfite cellulose liquor solids are those resulting from the concentration and drying of ordinary sulfite cellulose liquor produced in the manufacture of wood pulp. I do not wish to be limited to any particular process of concentration or drying nor is it important whether ingredients be added or re moved during such concentration and drying. For instance the fermentable ingredients may or may not be removed. Preferfurnace slag and the magnesium sulfate have been mixed and spread, and in'that case the sulfite cellulose powder may be omitted from the dry binder composition, or the percent of the dry powder materially reduced and the amounts made up by equivalent solids in the sulfite cellulose liquor used as a sprinkling or wetting down agent. It is preferable to use the powder and wet down with Water as a more thorough mixing is obtained in this way. I

Having thus described my invention what 1 claim as new and desire to secure by Letters Patent is:

1. A binder for mineral aggregates ineluding silicates which are attacked by hydrochloric acid and sulfite cellulose liquor.

2. A dry powder for use as a binder for mineral aggregates, including silicates which are attacked by hydrochloric acid, sulfite cellulose powder.

3. A dry powder for use as a binder for mineral aggregates, including silicates which are attacked by hydrochloric acid, sulfite cellulose powder and magnesium sulfate.

4. A binder including blast furnace slag, solids of sulfite cellulose liquor and magnesium sulfate.

5. A binder including blast furnace slag, solids of sulfite cellulose liquor of an acid reaction and magnesium sulfate.

6. A binder in dry powder form including substantially 82% blast furnace slag, substantially 11% sulfite cellulose liquor and substantially 7% magnesium sulfate.

7. A process of making a binding for the mineral aggregate of road ways, comprising effecting a reaction between a finely ground silicate which is attacked by hydrochloric acid and sulfite cellulose liquor by moisture and the abrading action of pressure on the mineral aggregate.

8. The process of making a road way which includes mixing mineral aggregates and powder, including blast furnace slag,

sulfite cellulose powder and magnesium sulfate, wetting and rolling.

9. The process of making a road way, including mixing with mineral aggregate a dry finely subdivided mixture of blast furnace slag, sulfite cellulose and magnesium sulfate and effecting a chemical reaction by moisture and pressure and resulting in a hard, solid, impervious mass.

Signed at Trenton, in the county of Mercer and State of New Jersey, this 30th day of July, A. D. 1921.

JACOB SHOTWELL ROBESON. 

